Motherboard mounted computer graphics cards are known which provide dual display output. When made for two displays, also known as a dual-head mode, the graphics card can operate with the first display or head either as a digital flat panel output (DVI) or a standard analog monitor output (HD-15). The second head can be a standard analog monitor output RGB (HD-15) or television (Mini-din or RCA).
Since it is not mechanically possible to fit all five connectors in the I/O bracket opening (DVI, HD-15, HD15, Mini-Din, RCA), choosing which connections will make up the dual-head configuration must be made. Thus, if it is not possible to put all five connectors on one I/O card, multiple variations of cards must be designed.
In an ATX form factor, one would have to design four different I/O cards to support all modes of operation of dual head product capabilities. These fours variations are;    1) Digital flat panel (DVI) and analog monitor (HD-15).    2) Digital flat panel (DVI) and video (Mini-din and RCA).    3) Analog monitor (HD-15) and analog monitor (HD-15).    4) Analog monitor (HD-15) and video (Min-din and RCA).
One attempt to reduce the number of I/O card configurations by half, is to use a breakout cable as an adapter. This adapter converts an HD-15 connector into two video connectors, the mini-DIN4 and RCA. Thus, for the second head, all I/O cards would have an HD-15 connector, and with the help of this break-out cable, either an analog monitor or TV/VCR can be connected. However, even with this breakout cable, two cards still need to be designed; card 1 and card 3 described above.
To reduce further the number of boards to design from 2 to 1, one can provide only one board with a DVI connector and provide a DVI to HD-15 adapter. However, the combined cost of the adapter and the DVI board connector is expensive.
In addition to the connector combination needs for the ATX form factor dual-head graphics card, a similar set of combinations for the NLX form factor is required. The NLX was designed to improve upon today's low form factors and to adapt to new market trends and PC technologies. The NLX form factor is an attempt at incorporating flexibility to accommodate the best designs for current and future PC's.
Since the NLX motherboard specification accommodates the use of double width connectors across half of the rear I/O and single high across the whole maximum board width, the I/O card must be designed with this form factor in mind. Therefore, the combinations of (DVI and HD-15), (HD-15 and HD-15), (HD-15 and Mini-din and RCA), and (DVI and Mini-din and RCA) cannot be connected by mounting directly above each other on the I/O card as is possible with the ATX form factor. Instead, a special module must be designed that attaches to the baseboard and has the second connector mounted in a double width connector bracket. This is the standard solution for NLX form factor cards having dual I/O connectors. In an NLX form factor, one would have to design four different I/O cards to support all modes of operation of dual head product capabilities. These four variations are:    1) Digital flat panel (DVI).    2) Analog monitor (HD-15).    3) Analog monitor (HD-15) module.    4) Video (Mini-din and RCA) module.
In order to achieve the same dual head product capabilities as with the ATX form factor the four variations outlined above must be combined in the following way:    1) Digital flat panel (DVI) with analog monitor (HD-15) module.    2) Digital flat panel (DVI) with video (Mini-din and RCA) module.    3) Analog monitor (HD-15) with analog monitor (HD-15) module.    4) Analog monitor (HD-15) with video (Mini-din and RCA) module.
Although the NLX form factor changes have resulted in a reduction in overall system level cost for the computer, there has been an increase in cost for the I/O card manufacturers as they have to design specific I/O cards to fit the NLX form factor. If the same options in the NLX form factor as in the ATX form factor were to be provided, eight I/O cards would have to be designed.